This invention pertains to tools useful in servicing earth wells and particularly running and pulling tools usually used in wireline tool strings to run, operate in and pull tools from a well.
Many forms of running tools, pulling tools, and combination running and pulling tools have been developed to engage external and internal fishing necks on well tools to be run into or pulled from wells on pipe or wireline. Weight or pull is applied to running and pulling tools or they are "jarred", either upwardly or downwardly, to engage tool fishing necks on tools installed in wells, to lock, unlock or operate well tools while engaged and to release from a fishing neck after locking the tool or if the tool cannot be jarred to unlock and be retrieved from the well.
One form of a pulling tool is shown in U.S. Pat. No. 3,051,239 to Dollison. This tool engages an internal fishing neck and can only be released from the fishing neck by jarring downwardly and cannot be released if the tool mandrel or attached prong contacts inside an engaged fishing neck before the tool skirt contacts the top end of a fishing neck. Also this tool was found to be expensive to manufacture because of close parts tolerances required to strengthen the tool to resist repeated jar impacting and is difficult to release from tool fishing necks manually on the surface.
As well servicing art and tools developed, requirements arose for this type running pulling tool to be jarred upwardly to cause release from a well tool fishing neck. As shown on page 115 of OTIS WIRELINE SUBSURFACE FLOW CONTROLS AND RELATED SERVICE EQUIPMENT, OEC 5121C, a publication of Otis Engineering Corporation, Dallas, Tex., a "GU" shear up adapter was made available to convert the modified "GS" running and pulling tool covered by the Dollison patent into a jar upwardly to release tool. This tool must be assembled with the adapter on the surface as a jar upwardly to release tool or without adapter for a jar downwardly to release tool, before running into the well.
An example of a pulling tool which engages an external fishing neck is covered by U.S. Pat. No. 4,558,895 to Tamplen. This tool must also be assembled on the surface for either upward jar release or downward jar release.
The improved running pulling tool of this invention provides a tool which may be repeatedly jarred downwardly to upwardly as required after engaging an internal fishing neck and later be released from the fishing neck at any desired time by downward jarring. This tool will release when jarred downwardly on contact of either the lower end of the mandrel with the inside of the engaged fishing neck or by contact of the lower end of the skirt with the top of the finishing neck. The lower housing skirt may be positioned to eliminate clearances between assembled parts, which gives the tool extended impact life, permits looser part tolerances and reduces manufacturing costs. After the invention tool has pulled a well tool to the surface, the improved pulling tool may be easily released from the well tool fishing neck with a common hand tool.
One object of this invention is to provide one tool which may be used to run or pull well tools from a well.
Another object of this invention is to provide a running pulling tool which, after engaging a well tool fishing neck, may be either jarred upwardly or jarred downwardly as long as required.
Another object of this invention is to provide a running pulling tool which may be released from a fishing neck at any time after engagement therewith.
Another object of this invention is to provide a running pulling tool which does not have to be retrieved to surface to reverse jarring direction for release.
Another object of this invention is to provide a running pulling tool which, when jarred down, will operate if the tool contacts the well tool fishing neck or if the tool mandrel contacts the well tool.
Also an object of this invention is to provide a less expensive running pulling tool not requiring precisely manufactured parts.
Another object of this invention is to provide a running pulling tool having improved impact resistance when jarred upwardly.